Heim, Michael H. <br/><br/>
The metaphysics of virtual reality / 
Michael Heim 
 - New York :  Oxford University Press,  1993 
 - xxiii, 175 p. ;  24 cm. 
<br/><br/>p. 162-170 
<br/><br/><label>ISBN: </label>0195081781  RM76.14 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Human-computer interaction<br/>Virtual reality<br/>Technology--Social aspects